Found by running:
```
make pyupgrade
ruff check --fix .
ruff check --preview --unsafe-fixes --select=F401 --fix .
make format
make update-client-api-schema
```
The bulk of the changes are replacements of typing deprecated aliases
such as `Dict` and `List` with the standard library classes. These
aliases became redundant in Python 3.9 when the corresponding
pre-existing classes were enhanced to support `[]`, see
https://docs.python.org/3/library/typing.html#deprecated-aliases
Also:
- Update the `pyupgrade` Makefile target to use `--py38-plus` for the
packages needed by Pulsar, including the new galaxy-tool-util-models
package.